I didn't dislike her because of anything she did, I just didn't like how the character was written as knowing all these secrets about the Doctor. I don't know I find a character more compelling when they are at a disadvantage instead of an advantage. She just came off as Mary Sueish to me at first.

In this season though there are clues that she isn't everything that she seems. Finding out the mystery of River Song is very interesting to me. :)